Define: Burden Of Proof

Quick Summary of Burden Of Proof

The burden of proof is the level of proof one party must prove for a disputed assertion. Civil cases have a burden of proof which is described as a “preponderance of the evidence.” In a criminal case, however, the plaintiff (the government) must prove “beyond a reasonable doubt” to get a criminal conviction.

In a criminal case, the burden of proof resides with the state and the state must prove the defendant is guilty. The defendant does not have to prove anything (unless they are claiming insanity, duress or self-defence as their defence), and they are assumed innocent until proven guilty.

In civil law, the burden of proof is on the plaintiff (exceptions exist) and the plaintiff can win their case if they can prove a “preponderance of evidence” in their favour, although some cases such as fraud require a higher level of proof called “clear and convincing evidence.” So for a general civil claim, the jury may find for the plaintiff if they believe there is more than a 50% probability that the defendant was negligent in causing the plaintiff’s injury.

In a court hearing or trial, the side with the burden of proof is the side that has the task of proving the facts to the satisfaction of the judge or jury. The rules about which side bears the burden of proof have to be considered for both criminal and civil actions.

In English criminal law, the burden of proof generally lies with the prosecution; it has to prove all the facts that establish the guilt of the accused, except those that are assumed to be obvious (see judicial notice). The standard of proof is nearly always beyond a reasonable doubt.

If the prosecution does not discharge the burden of proof to the requisite standard, the accused will be acquitted. See R v. Woolmington (1935) for a textbook example.

However, some statutory and common-law provisions have the effect of shifting the burden of proof to the defendant. For example, the prosecution does not have a duty to prove that the defendant is sane or was incapable of moral reasoning. If these points are used as a defence, then the defendant will generally have to prove them, at least to the ‘balance of probabilities’ standard (see a reverse burden of proof). In addition, there are many cases in which the defendant may carry an evidential burden; that is, the defendant will have to adduce evidence to support his case, although he may not be required to prove it.

In a civil hearing, the side that brings the action usually has the burden of proof overall, although a more accurate rule is that the one who asserts must prove.

In some trials or hearings, the determination of the burden of proof is straightforward. More often, however, there are subsidiary matters to the main facts in issue, and the question then arises: who has the burden of proving those? There are many technicalities concerning the burden of proof in such cases, some of which are created by statute and some of which have been developed by the courts over a period of time. What follows are a few examples; you should not assume that this is an inclusive list by any means.

1. In a criminal trial, the side that wishes to adduce evidence has the burden of proving that it is admissible (see admissibility of evidence). For example, if the defendant wishes to adduce evidence that might be regarded as hearsay and this evidence is contested by the prosecution, the defence will have to prove that the evidence is not hearsay or that it falls within one of the exceptions to the hearsay rule.
2. In a criminal trial, if the defendant argues that his confession was extracted under duress, then s.76 of Pace imposes on the prosecution the duty of proving that this was not the case and that the confession was made freely.
3. In a civil action for breach of contract, a party who wishes to rely on an exclusion clause—whether that party is the claimant or the defendant—must show that the clause was validly incorporated into the contract.
4. In an action in Tort, it is now generally accepted that a plea of res ipsa loquitur does not have the effect of shifting the burden of proof to the defendant. It does, however, create for the defendant an obligation to raise some evidence to show that he was not at fault.

Types Of Burden

There are generally three broad types of burdens.

• A “legal burden” or a “burden of persuasion” is an obligation that remains on a single party for the duration of the claim. Once the burden has been entirely discharged to the satisfaction of the trier of fact, the party carrying the burden will succeed in its claim. For example, the presumption of innocence places a legal burden upon the prosecution to prove all elements of the offence (generally beyond a reasonable doubt) and to disprove all the defences except for affirmative defences, in which the proof of the nonexistence of all affirmative defense(s) is not constitutionally required of the prosecution (432 U.S. 197).
• An “evidentiary burden” or “burden of leading evidence” is an obligation that shifts between parties over the course of the hearing or trial. A party may submit evidence that the court will consider prima facie proof of some state of affairs. This creates an evidentiary burden upon the opposing party to present evidence to refute the presumption.
• A “tactical burden” is an obligation similar to an evidentiary burden. Presented with certain evidence, the Court has the discretion to infer a fact from it unless the opposing party can present evidence to the contrary.

Standard Of Proof

The “standard of proof” is the level of proof required in a legal action to discharge the burden of proof, ie convince the court that a given proposition is true. The degree of proof required depends on the circumstances of the proposition. Typically, most countries have two levels of proof: “the balance of probabilities” (BOP), called the “preponderance of evidence” in the U.S. (which is the lowest level, generally thought to be greater than 50%, although numeric approximations are controversial), and “beyond a reasonable doubt” (which is the highest level but defies numeric approximation). In addition to these, the U.S. introduced a third standard called “clear and convincing evidence”, (which is the medium level of proof).

The first attempt to quantify reasonable doubt was made by Simon in 1970. In her attempt, she presented a trial to groups of students. Half of the students decided the guilt or innocence of the defendant. The other half recorded their perceived likelihood, given as a percentage, that the defendant committed the crime. She then matched the highest likelihoods of guilt with the guilty verdicts and the lowest likelihoods of guilt with the innocent verdicts. From this, she gauged that the cut-off for reasonable doubt fell somewhere between the highest likelihood of guilt matched to an innocent verdict and the lowest likelihood of guilt matched to a guilty verdict. From these samples, Simon concluded that the standard was between 0.70 and 0.74.

Air Of Reality

The “air of reality” is a standard of proof used to determine whether a criminal defence may be used. The test asks whether a defence can be successful if it is assumed that all the claimed facts are true.

Reasonable Suspicion

Reasonable suspicion is a low standard of proof in the U.S. to determine whether a brief investigative stop or a brief search by a police officer or any government agent is warranted. In Terry v. Ohio, the United States Supreme Court ruled that reasonable suspicion requires specific, articulable, and individualised suspicion that crime is afoot. A mere guess or “hunch” is not enough to constitute reasonable suspicion. As a result of the low threshold, the extent of intrusiveness of the search and/or seizure allowed is lower than the extent of intrusiveness allowed when a government agent has probable cause to suspect that evidence of a crime will be found.

A good illustration of this is the continuum of a typical police-citizen interaction:

Consensual encounter between officer and citizen (no level of suspicion required) →a stop initiated by the officer that would cause a reasonable person to feel that he/she is not free to leave (reasonable suspicion required) arrest (probable cause required).

Probable Cause For Arrest

Probable cause is a relatively low standard of evidence which is used in the United States to determine whether a search or an arrest is warranted. It is also used by grand juries to determine whether to issue an indictment. In the civil context, this standard is often used when plaintiffs are seeking a prejudgment remedy.

In the criminal context, the U.S. Supreme Court in United States v. Sokolow determined that probable cause requires “a fair probability that contraband or evidence of a crime will be found” in determining whether Drug Enforcement Administration agents had a reason to execute a search. Courts vary when determining what constitutes a “fair probability,” some say 30%, others 40%, others 51%.

Balance Of Probabilities

Also known as the “preponderance of evidence”, this is the standard required in most civil cases. The standard is met if the proposition is more likely to be true than not. Effectively, the standard is satisfied if there is greater than 50% chance that the proposition is true. Lord Denning in Miller v. Minister of Pensions described it simply as “more probable than not.

Clear And Convincing Evidence

Clear and convincing evidence” is the highest level of burden of persuasion sometimes employed in U.S. civil procedure. To prove something by “clear and convincing evidence”, the party with the burden of proof must convince the trier of fact that it is substantially more likely than not that the thing is in fact true. This is a lesser requirement than “proof beyond a reasonable doubt”, which requires that the trier of fact be close to certain of the truth of the matter asserted, but a stricter requirement than proof by “preponderance of the evidence,” which merely requires that the matter asserted seems more likely to be true than not.

Beyond Reasonable Doubt

This is the standard required by the prosecution in most criminal cases within an adversarial system. This means that the proposition being presented by the government must be proven to the extent that there is no “reasonable doubt” in the mind of a reasonable person that the defendant is guilty. There can still be a doubt, but only to the extent that it would not affect a “reasonable person’s” belief that the defendant is guilty. If the doubt that is raised does affect a “reasonable person’s” belief that the defendant is guilty, the jury is not satisfied beyond a “reasonable doubt. The precise meaning of words such as “reasonable” and “doubt” are usually defined within jurisprudence of the applicable country. In the United States, it is usually reversible error to instruct a jury that they should find guilt with a certain percentage of certainty (such as 90% certainty). Usually, reasonable doubt is defined as “any doubt which would make a reasonable person hesitate in the most important of his or her affairs.”

Examples

Criminal law

In most western countries, criminal cases place the burden of proof on the prosecutor, sometimes referred to by the latin legal expression “ei incumbit probatio qui dicit, non que negat” (the burden of proof rests on who asserts, not on who denies). The principle that it should be is known as the presumption of innocence, but is not upheld in all legal systems or jurisdictions. Where it is upheld, the accused will be found not guilty if this burden of proof is not sufficiently carried by the prosecution.

For example, if the defendant (D) is charged with murder, the prosecutor (P) bears the burden of proof to show the jury that D did murder someone.

• Burden of proof: P
  • Burden of production: P has to show some evidence that D had committed murder. The United States Supreme Court has ruled that the Constitution requires enough evidence to justify a rational trier of fact to find guilt beyond a reasonable doubt. If the judge rules that such burden has been met, then of course it is up to the jury itself to decide if they are, in fact, convinced of guilt beyond a reasonable doubt. See Jackson v. Virginia, 443 U.S. 307 (1979). If the judge finds there is not enough evidence under the standard, the case must be dismissed (or a subsequent guilty verdict must be vacated and the charges dismissed).
    e.g. witness, forensic evidence, autopsy report
    Failure to meet the burden: the issue will be decided as a matter of law (the judge makes the decision); in this case, D is presumed innocent
  • Burden of persuasion: if, at the close of evidence, the jury cannot decide if P has established with relevant level of certainty that D had committed murder, the jury must find D not guilty of the crime of murder
  • Measure of proof: P has to prove every element of the offence beyond a reasonable doubt, but not necessarily every single fact beyond a reasonable doubt.
    In some countries (Mexico and Mainland China are well-known examples), criminal law reverses the burden of proof. The defendant is presumed guilty until proven innocent. This type of standard is considered so manifestly unfair in most cases that countries that use it are considered totalitarian.

However, in England and Wales, the Magistrates’ Courts Act 1980, s. 101, stipulates that where a defendant relies on some “exception, exemption, proviso, excuse, or qualification” in his defence, the legal burden of proof as to that exception falls on the defendant, though only on the balance of probabilities. For example, a person charged with being drunk in charge of a motor vehicle can raise the defence that there was no likelihood of his driving while drunk.[3] The prosecution have the legal burden of proof beyond reasonable doubt that the defendant exceeded the legal limit of alcohol and was in control of a motor vehicle. Possession of the keys is usually sufficient to prove control, even if the defendant is not in the vehicle and is perhaps in a nearby bar. That being proved, the defendant has the legal burden of proof based on the balance of probabilities that he was not likely to drive.[4]

Similar rules exist in trial on indictment. Some defences impose an evidential burden on the defendant, which, if met, imposes a legal burden on the prosecution. For example, if a person charged with murder pleads for the right to self-defence, the defendant must satisfy the evidential burden that there are some facts suggesting self-defence. The legal burden will then fall on the prosecution to prove beyond reasonable doubt that the defendant was not acting in self-defence.[4]

In 2002, such practice in England and Wales was challenged as contrary to the European Convention on Human Rights (ECHR), Art. 6(2), guaranteeing the right to a fair trial. The House of Lords held that such burdens were not contrary to the ECHR. [4][5]

• A mere evidential burden did not contravene Art. 6(2).
• A legal or persuasive burden did not necessarily contravene Art. 6(2) so long as it was confined within reasonable limits, considering the questions:
  • What must the prosecution prove to transfer burden to the defendant?
  • Is the defendant required to prove something difficult or easily within his reach?
  • What is threat to society that the provision is designed to combat?

Civil Law

In civil law cases, the “burden of proof” requires the plaintiff to convince the trier of fact (whether judge or jury) of the plaintiff’s entitlement to the relief sought. This means that the plaintiff must prove each element of the claim, or cause of action, in order to recover.

The burden of proof must be distinguished from the “burden of going forward,” which simply refers to the sequence of proof between the plaintiff and defendant. The two concepts are often confused.

Decisions By The U.S. Supreme Court

The Supreme Court discussed how courts should allocate the burden of proof (i.e., the burden of persuasion) in Schaffer ex rel. Schaffer v. Weast, 546 U.S. 49 (2005). The Supreme Court explained that if a statute is silent about the burden of persuasion, the court will “begin with the ordinary default rule that plaintiffs bear the risk of failing to prove their claims.” In support of this proposition, the Court cited 2 J. Strong, McCormick on Evidence § 337, 412 (5th ed. 1999), which states, “The burdens of pleading and proof with regard to most facts have been and should be assigned to the plaintiff who generally seeks to change the present state of affairs and who therefore naturally should be expected to bear the risk of failure of proof or persuasion.

At the same time, the Supreme Court also recognised that “the ordinary default rule, of course, admits exceptions.” “For example, the burden of persuasion as to certain elements of a plaintiff’s claim may be shifted to defendants when such elements can fairly be characterised as affirmative defences or exemptions. See, e.g., FTC v. Morton Salt Co., 334 U.S. 37, 44–45 (1948). Under some circumstances, this Court has even placed the burden of persuasion over an entire claim on the defendant. See Alaska Dept. of Environmental Conservation v. EPA, 540 U.S. 461, 494 (2004). ” Nonetheless, there is some reason to believe that Congress intended otherwise; therefore, [the Supreme Court] will conclude that the burden of persuasion lies where it usually falls: upon the party seeking relief.

In Director, Office of Workers’ Compensation Programmes v. Greenwich Collieries, 512 U.S. 267 (1994), the Supreme Court explained that “burden of proof” is ambiguous because it has historically referred to two distinct burdens: the “burden of persuasion” and the “burden of production.”

In Keyes v. Sch. Dist. No. 1, 413 U.S. 189 (1973), the Supreme Court stated: “There are no hard-and-fast standards governing the allocation of the burden of proof in every situation. The issue, rather, ‘is merely a question of policy and fairness based on experience in the different situations.'” For support, the Court cited 9 John H. Wigmore, Evidence § 2486, at 275 (3d ed. 1940). In Keyes, the Supreme Court held that if “school authorities have been found to have practiced purposeful segregation in part of a school system,” the burden of persuasion shifts to the school to prove that it did not engage in such discrimination in other segregated schools in the same system.

Science And Other Uses

Outside a legal context, “burden of proof” means that someone suggesting a new theory or stating a claim must provide evidence to support it; it is not sufficient to say, “You can’t disprove this.” Specifically, when anyone makes a bold claim, it is not someone else’s responsibility to disprove the claim, but rather the responsibility of the person who is making the bold claim to prove it. In short, X is not proven simply because “not X” cannot be proven (see negative proof).

Taken more generally, the standard of proof demanded to establish any particular conclusion varies with the subject under discussion. Just as there is a difference between the standard required for a criminal conviction and a civil case, there are different standards of proof applied in many other areas of life.

The less reasonable a statement seems, the more proof it requires. The scientific consensus on cold fusion is a good example. The majority believes this can not really work, because believing that it would do so would force the alteration of a great many other tested and generally accepted theories about nuclear physics.

A classic example comes from Criswell’s final speech at the end of Ed Wood’s Plan 9 from Outer Space: “My friends, you have seen this incident, based on sworn testimony. Can you prove that it didn’t happen?”. Considering that the incident in question involved grave robbers from space, the burden of proof is being incorrectly assigned.

A humorous example comes from the television series Futurama during the opening credit gag for the episode Obsoletely Fabulous states regarding the premise of the show: ‘You can’t prove it won’t happen’.

Disclaimer

This site contains general legal information but does not constitute professional legal advice for your particular situation. Persuing this glossary does not create an attorney-client or legal adviser relationship. If you have specific questions, please consult a qualified attorney licensed in your jurisdiction.

This glossary post was last updated: 9th April, 2024.